|Publication number||US20030031752 A1|
|Application number||US 09/925,928|
|Publication date||Feb 13, 2003|
|Filing date||Aug 10, 2001|
|Priority date||Aug 10, 2001|
|Also published as||US6659760|
|Publication number||09925928, 925928, US 2003/0031752 A1, US 2003/031752 A1, US 20030031752 A1, US 20030031752A1, US 2003031752 A1, US 2003031752A1, US-A1-20030031752, US-A1-2003031752, US2003/0031752A1, US2003/031752A1, US20030031752 A1, US20030031752A1, US2003031752 A1, US2003031752A1|
|Inventors||Hsueh-Hsin Liao, Chung-Ming Hung|
|Original Assignee||Hsueh-Hsin Liao, Chung-Ming Hung|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (5), Classifications (8), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
 The present invention relates to a mechanism in a plastic injection machine and the mechanism ensures the screw rod to be precisely moved together with the open and close of the molds.
 A conventional plastic injection molding machine for manufacturing products having screw holes generally employs a gear system for controlling a screw rod moving into or removing from the cavity between two molds. The gear system is controlled by electric control system. The gear system including too many gears which is a load of maintenance. The gear system is difficult to precisely move the screw rod relative the molds so that the depth of the screw rod in the cavity cannot be obtained the same each time when the plastic material is injected into the cavity. The screw hole of the products could be damaged if the screw rod cannot be removed from the molds in stable. The gear system is activated after the movement of the molds is finished so that it prolongs the period of the complete process.
 In accordance with one aspect of the present invention, there is provided a plastic injection molding machine which comprises a position block on the upper mold and a slide member on the lower mold. A pin is inserted in the position block and the movable member. A rod extends through the slide member so that the top end of the rod is inserted in the cavity when the pin is inserted in the slide member. Two side members each have threaded semi-circular recesses which are engaged with a threaded section on the rod so that when the rod is rotated by a motor, the rod is smoothly removed from the cavity.
 The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
FIG. 1 is an exploded view to show the plastic injection molding machine of the present invention;
FIG. 2 is a perspective view to show the plastic injection molding machine of the present invention;
FIG. 3 is a cross sectional view to show two side members are moved away from the rod when two pins are inserted in the two respective top holes in the side members;
FIG. 4 is a perspective view to show the tip end of the rod is sent in the cavity between the two molds, and
FIG. 5 is a cross sectional view to show the two side members are biased toward the rod when two pins are removed from the top holes in the side members.
 Referring to FIGS. 1 and 2, the plastic injection molding machine of the present invention comprises an upper mold 11 having a position block 20 connected thereto which has an first inclined hole 21 defined therethrough. A lower mold 12 is located beneath the upper mold 11 and a slide member 40 is located beside the lower mold 12. The slide member 40 has a second inclined hole 41 which is located in alignment with the first inclined hole 21. A pin 30 is movably inserted in the first inclined hole 21 and an end of the pin 30 can be movably inserted in the second inclined hole 41 to move the slide member 40 toward the cavity between the upper mold 11 and the lower mold 12. A recess 43 is defined in a top of the slide member 40 and a U-shaped engaging member 44 is engaged with the recess 43. Two apertures 42 are respectively defined through two parts of the slide member 40 separated by the recess 43.
 A base 500 has a rod 50 movably inserted therethrough, and the rod 50 has a first threaded section 51 on a first end thereof and a second threaded section 52 located close to a second end of the rod 50. The first threaded section 52 and the second threaded section 51 have the same thread pitch. A flange 53 extends radially outward from an outer periphery of the rod 50 and is located between the first threaded section 51 and the second threaded section 52. The first end of the rod 50 extends through the apertures 42 of the slide member 40 and the engaging member 44 so that the first threaded section 51 may be located in a cavity between the upper mold 11 and the lower mold 12 and when the plastic material is injected into the cavity, a threaded recess can be formed around the first threaded section 51. The flange 53 is engaged with the engaging member 44 so that the rod 50 is moved with the slide member 40. A sensor 54 and a motor 60 are respectively connected to the second end of the rod 50.
 Two side members 80 each have a semi-circular threaded recess 81 and the second threaded section 52 is located between the two semi-circular threaded recesses 81 of the two side members 80. Each of the side members 80 is biased by a spring 82 which urges the side member 80 toward the rod 50. Each of the side members 80 has a top hole 83 and two guide rods 70 are movably inserted in the two respective top holes 83 of the two side members 80. As shown in FIG. 3, when the two guide rods 70 are inserted in the two top holes 83, the two side members 80 are pushed away from the second threaded section 52 of the rod 50. In the meanwhile, the tip end 31 of the pin 30 is inserted into the second inclined hole 41 to move the slide member 40 and the rod 50 so that the first threaded section 51 of the rod 50 is inserted into the cavity and the upper mold 11 and the lower mold 12 are close to each other and plastic material is injected in the cavity.
 As shown in FIGS. 4 and 5, when the upper mold 11 and the lower mold 12 are to be separated from each other, the position block 20 is raised and the pin 30 is removed from the first inclined hole 21 and the second inclined hole 41. The two guide rods 70 are removed from the two top holes 83 of the side members 80 so that the two side members 80 are pushed by the springs 82 and the second threaded section 52 is threadedly engaged with the two threaded semi-circular recesses 81. The motor 60 is then activated to rotate the rod 50 to pull the rod 50 together with the slide member 40 back. The first threaded section 51 is then removed from the cavity. Because the pitch of the first threaded section 51, the second threaded section 52 and the threads in the threaded semi-circular recesses 81 are the same, so that the rod 50 can be smoothly moved back such that the threads formed in the final product will not be affected or damaged. When the rod 50 is moved to a desired position, the sensor 54 sends a message to stop the motor 60.
 While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7674106 *||Nov 30, 2006||Mar 9, 2010||Hon Hai Precision Industry Co., Ltd.||Molding apparatus|
|US7845926 *||Dec 4, 2008||Dec 7, 2010||Hon Hai Precision Industry Co., Ltd.||Mold apparatus for forming screw threads|
|US7846370 *||Sep 9, 2008||Dec 7, 2010||Hon Hai Precision Industry Co., Ltd.||Threaded core, injection molded apparatus method for making lens barrel|
|US20070092598 *||Jul 20, 2006||Apr 26, 2007||Hon Hai Precision Industry Co., Ltd.||Injection mold|
|CN101823321A *||May 10, 2010||Sep 8, 2010||宁海茂盛模具有限公司||Anti-retraction device of loose core of oil cylinder of injection mold|
|International Classification||B29C45/33, B29C45/44|
|Cooperative Classification||B29C45/332, B29C2045/4492, B29C45/44|
|European Classification||B29C45/33B, B29C45/44|
|Aug 10, 2001||AS||Assignment|
|Jun 5, 2007||FPAY||Fee payment|
Year of fee payment: 4
|May 26, 2011||FPAY||Fee payment|
Year of fee payment: 8
|Jul 17, 2015||REMI||Maintenance fee reminder mailed|